This invention relates to valuable cards, instruments and documents and, in particular, to a method and apparatus for preventing the counterfeiting and falsification of these cards, instruments and documents.
For ease of discussion, the invention will be illustrated using cards, such as debit cards (or cash value cards) which are issued to individuals in payment of a certain sum of money. These debit cards are also referred to as cash value cards or cash cards since they may be redeemed for cash or the equivalent in goods and/or services. In fact, a card holder uses the card when making withdrawals at a money dispensing or card acceptance machine. By way of example, as shown in FIG. 8A, a person may insert cash ($) into a card vending machine 95 and the card vending machine will issue a debit or cash value card 100. Subsequently, as shown in FIG. 8B, the purchaser of the card can insert the card 100 into a cash dispensing (card accepting) machine 97 to withdraw all or part of the cash value of the card 100.
In one application, each time the card holder makes a withdrawal, a hole is punched through the card to indicate the amount of the withdrawal. For example, assume that a card issued for payment of $2,000.00 has a value of $2,000.00 and that the $2000.00 card is arranged to have 20 units with each unit representing a value of $100.00. A card holder may then make partial cash withdrawals (receive payment) in units of $100.00, or the card holder may receive goods (e.g., tokens, chips, balls) or services meted out in units of $100.00. For each unit (e.g., $100.00) withdrawn, a hole is punched in the card to indicate that the value of the card has been decreased by one unit (e.g., $100.00). If a card has a value of 20 units, there can be a maximum of 20 unit holes punched in the card to indicate that the entire value of the card has been used up.
By way of example, a card 100 is shown in FIG. 1. The card has a strip 102 along which holes may be punched. Typically, as shown in FIG. 1, an issuance hole 1A is punched into the card by the card vending machine 95 at the time of the issuance of the card so as to validate the card. Subsequently, 20 additional holes (2-21) may be punched into the card by the cash dispensing machine 97 each time a withdrawal is made. Hole number 2 is punched into the card after the first unit value is used up (e.g., $100.00 is withdrawn). Subsequently, hole number 3 is punched into the card after the second unit value is used up (e.g., another $100.00 is withdrawn), and so on. Thus, if the card holder used up the 20 units of value on the card by making 20 individual withdrawals, there would be a hole at each of twenty positions, plus an additional card issuance hole for a total of twenty one holes. In some prior art applications, if the card purchaser used up two units at a single transaction, there would be a single hole at the two unit position. Likewise, if the card used up twenty units in a single transaction, there would be a single hole at the 20 unit position. In any event, in accordance with the prior art, one or more holes are punched into a cash card until all the holes are punched or until the last hole (unit 20) is punched.
A problem with the above scheme is that it is possible to falsify the value of the card by simply filling in the holes of the cards using an opaque material. After the holes in the card have been filled up, the counterfeiter (thief) can reuse the card as if it were new and make cash (or the equivalent) withdrawals for the full value of the underlying card. The counterfeiter can then reuse the card an indefinite number of times.
It is known to deter the efforts of a counterfeiter (or falsifier) by manufacturing the cash cards 100 with a hologram stripe 101 on which is formed a holographic type of image in the same plane as the one in which the holes are to be punched, as shown in FIG. 2. For such cards, the holes simply cannot be filled up by conventional methods to fool a dispensing machine. If there is a hole in the holographic image, it becomes very difficult, if not impossible, for a counterfeiter to fill up the hologram image without using some very expensive methods. Nevertheless, it is still possible for a counterfeiter to reuse a canceled card by cutting off a portion of the top of the hologram stripe (e.g., section 101A) above the holes; and then pasting the portion of the hologram stripe (101A) on the portion (101B) of a previously canceled card so that the holes are covered. Alternatively, a counterfeiter may produce a false hologram to place over a strip 101 even though its placement in an appropriate manner so as to fool a dispensing machine presents a significant problem. In either method, the counterfeiting process is then normally completed by punching an issuance hole in the first position (i.e., the card issuance position).
An object of the invention is to make the falsification of the value of a cash card or the counterfeiting of such cards extremely difficult, if not impossible.
As noted above, the cash card is an example of a particular application of the invention. It is an object of the invention to impede the counterfeiting and/or falsification of any valuable instrument/card/document. Therefore, note that in the discussion to follow and in the appended claims, when the term "instrument" is used without limitation, it is intended that the term "card" or "document" be included and vice-versa.